#ifdef FREEBSD
# include <machine/endian.h>
#elif defined(LINUX)
# include <endian.h>
#elif defined(SOLARIS)
# include <sys/isa_defs.h>
#endif
#if __BYTE_ORDER == __BIG_ENDIAN
#define HIGHFIRST 1
#endif
#include <stdint.h>
/*
 * This code implements the MD5 message-digest algorithm.
 * The algorithm is due to Ron Rivest.  This code was
 * written by Colin Plumb in 1993, no copyright is claimed.
 * This code is in the public domain; do with it what you wish.
 *
 * Equivalent code is available from RSA Data Security, Inc.
 * This code has been tested against that, and is equivalent,
 * except that you don't need to include two pages of legalese
 * with every copy.
 *
 * To compute the message digest of a chunk of bytes, declare an
 * MD5Context structure, pass it to MD5Init, call MD5Update as
 * needed on buffers full of bytes, and then call MD5Final, which
 * will fill a supplied 16-byte array with the digest.
 */
#include <string.h>    /* for memcpy() */
#include "md5_c.h"

#ifndef HIGHFIRST
#define byteReverse(buf, len)  /* Nothing */
#else
void byteReverse ( unsigned char *buf, unsigned longs );

#ifndef ASM_MD5 
/*
* Note: this code is harmless on little-endian machines.
*/
void byteReverse ( unsigned char *buf, unsigned longs ) {
  uint32_t t;

  do {
    t = ( uint32_t ) ( ( unsigned ) buf[ 3 ] << 8 | buf[ 2 ] ) << 16 |
        ( ( unsigned ) buf[ 1 ] << 8 | buf[ 0 ] );
    *( uint32_t * ) buf = t;
    buf += 4;
  }
  while ( --longs );
}

#endif
#endif

/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */

void MD5Init ( struct MD5Context *ctx ) {
  ctx->buf[ 0 ] = 0x67452301;
  ctx->buf[ 1 ] = 0xefcdab89;
  ctx->buf[ 2 ] = 0x98badcfe;
  ctx->buf[ 3 ] = 0x10325476;

  ctx->bits[ 0 ] = 0;
  ctx->bits[ 1 ] = 0;
}

/*
 * Update context to reflect the concatenation of another buffer full
 * of bytes.
 */

void MD5Update ( struct MD5Context *ctx, unsigned char const *buf,
                 unsigned len ) {
  uint32_t t;

  /* Update bitcount */

  t = ctx->bits[ 0 ];

  if ( ( ctx->bits[ 0 ] = t + ( ( uint32_t ) len << 3 ) ) < t )
    ctx->bits[ 1 ] ++;    /* Carry from low to high */

  ctx->bits[ 1 ] += len >> 29;

  t = ( t >> 3 ) & 0x3f;  /* Bytes already in shsInfo->data */

  /* Handle any leading odd-sized chunks */

  if ( t ) {
    unsigned char * p = ( unsigned char * ) ctx->in + t;

    t = 64 - t;

    if ( len < t ) {
      memcpy ( p, buf, len );
      return ;
    }

    memcpy ( p, buf, t );
    byteReverse ( ctx->in, 16 );
    MD5Transform ( ctx->buf, ( uint32_t * ) ctx->in );
    buf += t;
    len -= t;
  }

  /* Process data in 64-byte chunks */

  while ( len >= 64 ) {
    memcpy ( ctx->in, buf, 64 );
    byteReverse ( ctx->in, 16 );
    MD5Transform ( ctx->buf, ( uint32_t * ) ctx->in );
    buf += 64;
    len -= 64;
  }

  /* Handle any remaining bytes of data. */

  memcpy ( ctx->in, buf, len );
}

/*
 * Final wrapup - pad to 64-byte boundary with the bit pattern 
 * 1 0* (64-bit count of bits processed, MSB-first)
 */

void MD5Final ( unsigned char digest[ 16 ], struct MD5Context *ctx ) {
  unsigned count;
  unsigned char *p;

  /* Compute number of bytes mod 64 */
  count = ( ctx->bits[ 0 ] >> 3 ) & 0x3F;

  /* Set the first char of padding to 0x80.  This is safe since there is
     always at least one byte free */
  p = ctx->in + count;
  *p++ = 0x80;

  /* Bytes of padding needed to make 64 bytes */
  count = 64 - 1 - count;

  /* Pad out to 56 mod 64 */

  if ( count < 8 ) {
    /* Two lots of padding:  Pad the first block to 64 bytes */
    memset ( p, 0, count );
    byteReverse ( ctx->in, 16 );
    MD5Transform ( ctx->buf, ( uint32_t * ) ctx->in );

    /* Now fill the next block with 56 bytes */
    memset ( ctx->in, 0, 56 );
  }
  else {
    /* Pad block to 56 bytes */
    memset ( p, 0, count - 8 );
  }

  byteReverse ( ctx->in, 14 );

  /* Append length in bits and transform */
  ( ( uint32_t * ) ctx->in ) [ 14 ] = ctx->bits[ 0 ];
  ( ( uint32_t * ) ctx->in ) [ 15 ] = ctx->bits[ 1 ];

  MD5Transform ( ctx->buf, ( uint32_t * ) ctx->in );
  byteReverse ( ( unsigned char * ) ctx->buf, 4 );
  memcpy ( digest, ctx->buf, 16 );
  memset ( ctx, 0, sizeof ( ctx ) );  /* In case it's sensitive */
}

#ifndef ASM_MD5

/* The four core functions - F1 is optimized somewhat */

/* #define F1(x, y, z) (x & y | ~x & z) */
#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

/* This is the central step in the MD5 algorithm. */
#define MD5STEP(f, w, x, y, z, data, s) \
  ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )

/*
 * The core of the MD5 algorithm, this alters an existing MD5 hash to
 * reflect the addition of 16 longwords of new data.  MD5Update blocks
 * the data and converts bytes into longwords for this routine.
 */
void MD5Transform ( uint32_t buf[ 4 ], uint32_t const in[ 16 ] ) {
  register uint32_t a, b, c, d;

  a = buf[ 0 ];
  b = buf[ 1 ];
  c = buf[ 2 ];
  d = buf[ 3 ];

  MD5STEP ( F1, a, b, c, d, in[ 0 ] + 0xd76aa478, 7 );
  MD5STEP ( F1, d, a, b, c, in[ 1 ] + 0xe8c7b756, 12 );
  MD5STEP ( F1, c, d, a, b, in[ 2 ] + 0x242070db, 17 );
  MD5STEP ( F1, b, c, d, a, in[ 3 ] + 0xc1bdceee, 22 );
  MD5STEP ( F1, a, b, c, d, in[ 4 ] + 0xf57c0faf, 7 );
  MD5STEP ( F1, d, a, b, c, in[ 5 ] + 0x4787c62a, 12 );
  MD5STEP ( F1, c, d, a, b, in[ 6 ] + 0xa8304613, 17 );
  MD5STEP ( F1, b, c, d, a, in[ 7 ] + 0xfd469501, 22 );
  MD5STEP ( F1, a, b, c, d, in[ 8 ] + 0x698098d8, 7 );
  MD5STEP ( F1, d, a, b, c, in[ 9 ] + 0x8b44f7af, 12 );
  MD5STEP ( F1, c, d, a, b, in[ 10 ] + 0xffff5bb1, 17 );
  MD5STEP ( F1, b, c, d, a, in[ 11 ] + 0x895cd7be, 22 );
  MD5STEP ( F1, a, b, c, d, in[ 12 ] + 0x6b901122, 7 );
  MD5STEP ( F1, d, a, b, c, in[ 13 ] + 0xfd987193, 12 );
  MD5STEP ( F1, c, d, a, b, in[ 14 ] + 0xa679438e, 17 );
  MD5STEP ( F1, b, c, d, a, in[ 15 ] + 0x49b40821, 22 );

  MD5STEP ( F2, a, b, c, d, in[ 1 ] + 0xf61e2562, 5 );
  MD5STEP ( F2, d, a, b, c, in[ 6 ] + 0xc040b340, 9 );
  MD5STEP ( F2, c, d, a, b, in[ 11 ] + 0x265e5a51, 14 );
  MD5STEP ( F2, b, c, d, a, in[ 0 ] + 0xe9b6c7aa, 20 );
  MD5STEP ( F2, a, b, c, d, in[ 5 ] + 0xd62f105d, 5 );
  MD5STEP ( F2, d, a, b, c, in[ 10 ] + 0x02441453, 9 );
  MD5STEP ( F2, c, d, a, b, in[ 15 ] + 0xd8a1e681, 14 );
  MD5STEP ( F2, b, c, d, a, in[ 4 ] + 0xe7d3fbc8, 20 );
  MD5STEP ( F2, a, b, c, d, in[ 9 ] + 0x21e1cde6, 5 );
  MD5STEP ( F2, d, a, b, c, in[ 14 ] + 0xc33707d6, 9 );
  MD5STEP ( F2, c, d, a, b, in[ 3 ] + 0xf4d50d87, 14 );
  MD5STEP ( F2, b, c, d, a, in[ 8 ] + 0x455a14ed, 20 );
  MD5STEP ( F2, a, b, c, d, in[ 13 ] + 0xa9e3e905, 5 );
  MD5STEP ( F2, d, a, b, c, in[ 2 ] + 0xfcefa3f8, 9 );
  MD5STEP ( F2, c, d, a, b, in[ 7 ] + 0x676f02d9, 14 );
  MD5STEP ( F2, b, c, d, a, in[ 12 ] + 0x8d2a4c8a, 20 );

  MD5STEP ( F3, a, b, c, d, in[ 5 ] + 0xfffa3942, 4 );
  MD5STEP ( F3, d, a, b, c, in[ 8 ] + 0x8771f681, 11 );
  MD5STEP ( F3, c, d, a, b, in[ 11 ] + 0x6d9d6122, 16 );
  MD5STEP ( F3, b, c, d, a, in[ 14 ] + 0xfde5380c, 23 );
  MD5STEP ( F3, a, b, c, d, in[ 1 ] + 0xa4beea44, 4 );
  MD5STEP ( F3, d, a, b, c, in[ 4 ] + 0x4bdecfa9, 11 );
  MD5STEP ( F3, c, d, a, b, in[ 7 ] + 0xf6bb4b60, 16 );
  MD5STEP ( F3, b, c, d, a, in[ 10 ] + 0xbebfbc70, 23 );
  MD5STEP ( F3, a, b, c, d, in[ 13 ] + 0x289b7ec6, 4 );
  MD5STEP ( F3, d, a, b, c, in[ 0 ] + 0xeaa127fa, 11 );
  MD5STEP ( F3, c, d, a, b, in[ 3 ] + 0xd4ef3085, 16 );
  MD5STEP ( F3, b, c, d, a, in[ 6 ] + 0x04881d05, 23 );
  MD5STEP ( F3, a, b, c, d, in[ 9 ] + 0xd9d4d039, 4 );
  MD5STEP ( F3, d, a, b, c, in[ 12 ] + 0xe6db99e5, 11 );
  MD5STEP ( F3, c, d, a, b, in[ 15 ] + 0x1fa27cf8, 16 );
  MD5STEP ( F3, b, c, d, a, in[ 2 ] + 0xc4ac5665, 23 );

  MD5STEP ( F4, a, b, c, d, in[ 0 ] + 0xf4292244, 6 );
  MD5STEP ( F4, d, a, b, c, in[ 7 ] + 0x432aff97, 10 );
  MD5STEP ( F4, c, d, a, b, in[ 14 ] + 0xab9423a7, 15 );
  MD5STEP ( F4, b, c, d, a, in[ 5 ] + 0xfc93a039, 21 );
  MD5STEP ( F4, a, b, c, d, in[ 12 ] + 0x655b59c3, 6 );
  MD5STEP ( F4, d, a, b, c, in[ 3 ] + 0x8f0ccc92, 10 );
  MD5STEP ( F4, c, d, a, b, in[ 10 ] + 0xffeff47d, 15 );
  MD5STEP ( F4, b, c, d, a, in[ 1 ] + 0x85845dd1, 21 );
  MD5STEP ( F4, a, b, c, d, in[ 8 ] + 0x6fa87e4f, 6 );
  MD5STEP ( F4, d, a, b, c, in[ 15 ] + 0xfe2ce6e0, 10 );
  MD5STEP ( F4, c, d, a, b, in[ 6 ] + 0xa3014314, 15 );
  MD5STEP ( F4, b, c, d, a, in[ 13 ] + 0x4e0811a1, 21 );
  MD5STEP ( F4, a, b, c, d, in[ 4 ] + 0xf7537e82, 6 );
  MD5STEP ( F4, d, a, b, c, in[ 11 ] + 0xbd3af235, 10 );
  MD5STEP ( F4, c, d, a, b, in[ 2 ] + 0x2ad7d2bb, 15 );
  MD5STEP ( F4, b, c, d, a, in[ 9 ] + 0xeb86d391, 21 );

  buf[ 0 ] += a;
  buf[ 1 ] += b;
  buf[ 2 ] += c;
  buf[ 3 ] += d;
}

#endif

